Protective signal system



c. a. C. EGGERS 26,316 PROTECTIVE SIGNAL SYSTEM Filed Dec. 15, 1934 4 Sheets-Sheet 1 Clan awe C. E 8'5618 Filed Dec; 15, 1954 4 SheetsSheet 2 7 4.8 mu 7 F W: 7

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Am, Ev c. c. c. EGGERS PROTECTIVE SIGNAL SYSTEM Filed. Dec. 15, 1934 4 S heets-She6b4 Clarence Egger's- Patented Aug. 9, 1938 rre'r or ies PROTECTIVE SIGNAL SYSTEM Clarence C. C. Eggers, Minneapolis, Minn, assignor of one-half to Calvin E. Holmes, Minneapclis, Minn.

Application December 15, 1934, Serial No. 757,629

7 Claims.

My invention relates to protective signal systems and particularly to remotely operated systems for indication at a central station and has for an object to provide a system which may be used for the indication of burglaries, rise or fall in temperature, increase or reduction in pres sure or for any of the other uses for which protective systems may be employed.

An object of the invention resides in providing a system which is positive in action and which cannot be tampered with in any manner without causing actuation of the system and indication of the fault.

A still further object of the invention resides in providing a system in which the particular locality at Which the variation in condition or disturbance occurs can be indicated at the central station.

An object of the invention resides in providing a system including a circuit which is adapted to operatea signal if the circuit is grounded, or opened, 'or any portion thereof shunted out or shorted, or if any combination of shunting, shorting, grounding or opening any portion of the circuit is attempted.

An object of the invention resides in utilizing a circuit including a main line running from the central station to asubscribers station, said main line being connected at one end to a source of electrical energy disposed at the central station and being grounded at its other end in the central station. p

A still further object of the invention resides iirproviding at the central station in said line and at the grounded side thereof a relay and in providing at the subscribers station a protective device adapted to ,open said circuit in the event that the normal-condition of the circLL t at the subscribers station is disturbed.

Another object of the invention resides in providing at said central station a potential relay in said circuit and in further providing a resistance in series with said protective device and disposed in close proximity thereto.

An object of the invention resides in providing at said central station a signal circuit adapted to beenergized byelither or both of said relays, said signal circuit having one or more signals therein for indicating a defect in saidcircuit, tampering with or intentional operation of the system through said first named circuit.

Another" object of the invenion resides in providing a call device in said first named circuit and inproviding a recording devicein said signal circuit adapted to be operated by said call device.

A still further object of the invention resides in providing a secondary circuit at the subscribers station similar to said signal circuit at the central station for operating said call device.

A feature of the invention resides in providing asubscriberis operating circuit for closing said secondary circuit.

An object of the invention resides in disposing in said subscribers operating circuit a protective device for operating said circuit.

Another object of the invention resides in connecting said subscribers operating circuit at one end to a source of electrical energy and at its other end to the ground.

A feature of the invention resides in providing a relay having a coil connected in said subscribe1"s operating circuit at the grounded side thereof and having switch elements disposed in said secondary circuit.

Another object of the invention resides in providing a second potential relay having a coil connected in said subscribers operating circuit and having switch elements connected in said secondary circuit and in further providing a resistance inseries with said protective device and in close proximity thereto.

A still further object of the invention resides in utilizing a manually wound spring actuated call device and in providing an electrically operated trip device therefor, said trip device including an electromagnet connected in said subscribers operating circuit.

An object of the invention resides in the specific construction of said call device.

A feature of the invention resides in providing manually operated switches for closing and grounding said operating circuits.

An object of the invention resides in the specific construction of said switch and in the circuits' associated therewith.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

Inthe drawings:

Fig. 1 is a wiring diagram of my invention.

Fig. 2 is a side elevational view of the call device with the case and base therecf shown in section.

Fig. 3 is a sectional View taken on line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken on line 4-4 Fig. 2.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 3.

Fig. 6 is an elevational view of the cam key used with the invenion.

Fig. 7 is a wiring diagram of the portion of the system associated with the cam key shown in Fig. 6.

Fig. 8 is an across-the-line wiring diagram of the system shown in Fig. 1.

In designing protective systems it has heretofore been customary to provide a protective system for a single designated purpose as for example to indicate fire or burglary or failure of sprinkler systems or some other single purpose. The present invention provides a system which may be used for any and all such purposes and for any other purpose which the subscriber may desire without additional main lines. With the protective systems now in use a protective device may be rendered inoperative by competent mechanics so that the purpose of the system is obstructed and the system frequently fails to operate at the critical time. The present invention provides a device which may be used for any desired purpose and may be used for several desired purposes at one time and which cannot be tampered with without causing operation of the signal.

My invention as shown in Fig. 1, includes a signal circuit indicated in its entirety by the reference numeral l9 and an operating circuit therefor indicated in its entirety by the reference numeral 'The circuit H includes a main line l2 having sides I 3 and M which run between a central station C and a subscriber's station S. At the subscribers station S there are various substations a, b; c, d, e, f and g, at which stations suitable protective devices are installed, for indicating at the central station the existence of certain conditions at the subscribers station. At certain of the above named stations namely stations e, f and g, are located call devices l5, l6 and i! which are adapted to operate a recording device H3 in the signal circuit I and to designate in addition to giving the desired signal the particular station from which said signal originates. For the purpose of operating these call devices and to prevent tampering therewith or with the circuits connected with the same, a secondary circuit I9 is employed which is similar to the signal circuit In. This circuit is operated by a subscribers operating circuit 2| which is similar to the operating circuit previously referred to. These various circuits and the apparatus connected therein will now be described in detail.

Electrical energy is provided at the central station for both of the circuits l0 and H by means of a generator 22 which is connected on one side through a conductor 23 to the ground. The other sideis connected through a conductor 24 with two variable resistances 25 and 26 arranged in parallel. The generator 22 delivers a voltage considerably greater than that desired to be used in the circuits In and H and the resistances 25 and 26 are employed to cut down the voltage to that desired. The signal circuit It! includes a local line 28 which comprises two conductors 29 and 3|. Conductor 29 is directly connected to the resistance 25, being thereby connected to the potential side of the generator 22. Conductor 3| is directly connected to ground. In the signal circuit I8 is provided in addition to the recording device l8 a bell or other resonant signal 33, an annunciator 34 and a light 35. A conductor 32 forms part of the circuit I0 and is directly connected to the recording device l8,

Branch conductors 36 and 3! connect the conductor 32 with the bell 33 and the coil 38 of the annunciator 34. The annunciator 34 is constructed with a swinging armature 39 which operates a trip lever 4|. A swinging arm 42 is held in position by means of the trip lever 4|. When the armature 39 is articulated by the coil 38, arm 42 is released and drops downwardly to a position shown in dotted lines at 43. This arm forms part of the signalling circuit l0 and is adapted to engage a contact 44 when in its lowermost position. The contact 44 is connected through a conductor 45 with the lamp 35 while the arm 42 is connected through a conductor 46 with the conductor 29. The other side of the lamp 35 is directly connected to the conductor 3|.

The circuit H1 is normally open, being broken between the conductors 29 and 32. For the purpose of closing this circuit, three relays 41, 48 and 49 are employed which are constructed in the following manner: The relay 4'! is provided with a coil El and two contacts 52 and 53 adapted to be connected through a connector 54. Connector 54, is operated by a plunger 55 which is drawn into the coil when the said coil is enersized and serves to connect the contacts 52 and 53 together, thereby forming a switch which I have indicated in its entirety by the reference numeral 56. A spring 60 attached to connector 54 holds said switch open. The relay 41 is a potential relay and operates only when the potential across the coil 5| is increased beyond a normal predetermined potential insufficient to cause the closing of the switch 56. Relay 48 is constructed with a coil 51 and plunger 58 movable within the same. Plunger 58 operates a connector 59 which is adapted to connect together two contacts 6| and 62. These contacts and connector constitute another switch which I have indicated in its entirety by the reference numeral 64-. Coil 48 normally holds the switch 64 open and when said coil is deenergized the spring 63 draws the connector into engagement with contacts 6| and 62 and closes said switch. The relay 49 is identical with relay 48 and comprises a coil 65 and a plunger 66 movable Within the same. This plunger has attached to it a connector 68 which is adapted to connect together two contacts 69 and H and forms in conjunction therewith a switch indicated in its entirety by the reference numeral 12. A spring 13 similar to the spring 63 serves to close the switch 12 when the coil 65 is deenergized. Both of the relays 48 and 49 are current relays and are adapted to hold the switches 64 and 12 open as long as current flows through the coils 51 and. 65 and are adapted to close said switches when said coils are denergized.

The contact 52 of relay 4'! is connected through a conductor 14 with conductor 29 previously referred to. Another conductor 15 connects contact 53 with conductor 32. Contact 6| of relay 48 is connected through a conductor 16 with conductor 29 and contact 62 is connected through a conductor IT with conductor 32. Conductors 29 and 32 are directly connected to the contacts 69 and H of relay 49. It will thus be seen that the three switches 56, 64 and 12 are connected in parallel across the local line 28 forming part of the signal circuit l0 and that the operation of any or all of said relays will close the signal circuit and procure operation of the various signalling devices contained'in the same.

As previously stated, current for energizing the operating circuit II is procured from the generator 22. For this purpose the resistance 26 is employed which has connected to it a conductor II. This conductor is in turn Connected to a rheostat I02 which is further connected to a conductor Hi3. Conductor I03 feeds the various relays 41, 48 and 48 and is connected in the circuit II as will be presently described in detail.

For the purpose of testing the control circuit II two test jacks l8 and 79 are employed. The jack 18 comprises four leaves 8|, 82, 83 and 8d. The leaves BI and 82 are adapted to contact with one another and the leaves 33 and 84 are similarly adapted to contact with one another when the jack is in normal position. The two outer leaves SI and 84 are formed with extensions 85 and 8% which are adapted to be connected to a suitable test plug, not shown, when the same is inserted in the jack. Jack I9 is similarly constructed and consists of outer leaves 8'! and 88 and inner leaves 89 and 9! adapted to contact with the outer leaves. The outer leaves are constructed with extensions 92 and as which are adapted to be connected to the plug used for the testing of the circuit. It will be noted that the outer leaves of both of the jacks l8 and T9. are normally connected to the inner leaves and that when the outer leaves are spread apart and the plug inserted into the jack, the jack i8 is connected in the side Id of line l2 while the jack I9 is connected in side I3 of said line.

The manner of connecting the jacks in the circuit will now be described. Side it of line I2 is connected to leaf spring ill of jack it while a conductor 94; is connected to the other outer leaf 84 and to the other end of the coil 55 of relay $55. The other end of this coil is connected through a conductor 95 with the ground. The two leaves 82 and 83 of the jack it are connected together so that when the jack is in normal position continuity of the circuit occurs successively through the leaves 85, 82, 83 and 8d. The jack 19 is similarly connected. Side iii of line it is directly connected to the leaf 8i thereof, while the leaf 8B is connected to a conductor 85. This conductor is in turn connected to the end of coil 5i of relay 41. A branch conductor 9? is connected to the conductor 96 and is also connected to the other end of coil 5'! of relay it. The other ends of these relays are connected to a conductor 98 which in turn is connected to the conductor I63 previously referred to. It will thus be seen that the coil 65 of relay is is connected in the side Id of line it and is directly grounded and that the two coils 5i and lil of relays ll and it are connected in parallel and are in the other side 53 of the line, being disposed on the potential side of the line.

As previously stated the line It extends between the central station C and the subscribers station S, the said line being of any desired length and taking any suitable course necessary to connect the subscribers station with the central station. The remainder of the apparatus and the equipment utilized with the invention is situated at the subscribers station and at the various sub-- stations of the subscribers station. The portion of the circuit II at the subscribers station consists of a number of conductors which are connected to the various protective devices, said devices being all arranged in series in said circuit.

At the various sub-stations a, b, c, d, e, f and g, a protective device has been installed which is connected in the circuit ll. Inasmuch as the system may be used for various purposes, different types of protective devices have been shown and it can readily be comprehended that the type of device disclosed is merely illustrative and that any type of device may be substituted for that disclosed.

At station a I have shown a pressure responsive switch 403 which is particularly adapted to be used in conjunction with a sprinkler system. This switch includes a case Ilia which is provided with a chamber Hi5 within the interior thereof.

Case N34 is open at the front and is adapted to be closed by means of a diaphram H36 secured thereto through a retaining ring it! and machine screws I08. Diaphram It'd carries a contact I39 which is adapted to engage a contact ill, said contacts forming in conjunction a switch indicated in its entirety by the reference numeral I I2. The case IM is connected to a suitable pipe H3 which communicates with the water supply system of the sprinkler system. A spring I I4 acting between the diaphram Itt and case H34 holds the switch II 2 normally open. The. pipe H3 communicates with chamber I95 and when the pressure within the chamber W5 is normal, switch H2 is closed. If for. any reason the water pressure drops below normal, the diaphram Illil will be drawn inwardly through the action of spring I I4 and switch [I2 will open. This will cause the operation of the signalling system in a manner to be presently described in detail.

At stations b and c are located thermostats I I5 and till. The thermostat lit consists of a spiral ill of bi--metal which is adapted to contact with a fixed contact H8. This construction forms a switch H9 which is normally maintained closed. Thermostat Elli similarly consists of a spiral of bi-metal Ill which is adapted to engage a con tact 122. This construction provides a switch I23 which is also, normally closed. The thermostats H5 and H5 may be so constructed that the switches thereof open when an increase of temperature occurs. In such case the said thermostats are used for indicating fire or any abnormal rise in temperature such as might be occasioned in commercial plants where constant temperature is essential in the manufacture of its goods or products. The thermostats HE and Ill; may also be constructed so that the switches thereof open upon an abnormal drop in temperature. Such device may be advantageously used for safeguarding against freezing of water in pipes or other systems or for abnormal refrigeration or abnormal drop in temperature in any system.

At stations and 7 window foil 52d and IE has been illustrated as installed on two windows lift and Hill. This foil serves in the usual manner to give a signal when the window has been opened or broken or the circuit in any other manner tampered with at such locality. The foil IN and Hill is cemented to the window and forms a direct part of the circuit. method of use of the foil 1 Hill and E25 is obvious Said foil may be used in conjunction with any closure or structure which is apt to be broken or tampered with. It can readily be comprehended that a simple window switch may be substituted in place of the foil shown or may also be used in conjunction with the foil, if desired.

Where the protective system is to be used in a bank or similar place of business, it becomes frequently desirable to permit the attendants or cmployees in the bank to manually operate the system and give the signal. For this purpose cam keys I28 and I29 have been shown at stations (I scribed in detail,

With my improved invention the particular location of origin of the signal may be accurately indicated at the central station. This is accomplished through the various call devices I5, I6 and I1 which are situated at the desired substations in the subscribers station. With my invention some of the stations may have such call devices and other stations may be operated without the call device, a general alarm being in such case sounded. For the purpose of illustration, call devices have been shown at stations e, f and 9, though it can readily be comprehended that the said devices may be placed at any or all of the other stations shown, if desired. If the call devices were directly connected to the protective devices the same might be tampered with and shorted out so as to prevent the rendering of the signal. To overcome this disadvantage the cir cuits I9 and 2| have been employed in association with the call devices and the other equipment of the invention, which circuits will be subsequently more fully described.

Inasmuch as both of the cam keys I28 and I29 and the method of connecting up the same are identical, only the key I28 will be described in detail. The construction of the said key is shown in Fig. 6, while the wiring diagram for the portion of the circuit II associated therewith is shown in Fig. '1. The key I28 comprises a frame I3I, U- shaped in form which is constructed with two legs I32 and I33 and a connecting portion I34. Between the two legs I32 and I33 is mounted a bar I35 which is riveted or otherwise secured to the said two legs. This bar carries the various switch elements of the key. The switch elements of the key are formed through a number of switch leaves which are arranged in groups. There are four groups designated at I36, I31, I38 and I39 and the switch leaves in each group are similarly constructed. The two groups I36 and I31 are disposed on one side of the bar I35 while the groups I38 and I39 are disposed on the other side of said bar directly in back of the first named groups and the leaves thereof are hence not fully visible in Fig. 6. Group I36 includes three leaves I4I, I42 and I43 of which the inner leaf I42 is adapted to move between the leaves MI and I43 and to make contact with either thereof, depending upon the relative positions of said intermediate leaf. The leaves MI and I43 have contacts I44 and I45 which are adapted to directly engage the leaf I42. To limit the move" ment of the leaf I42 a rigid leaf I46 is employed which is disposed between the leaves I42 and I43. All of these leaves including the strip I46 are separated from one another through insulating spacers I41 and. the entire group is held in place by means of screws I48 which pass through the said leaves and spacers and are insulated from the leaves through sleeves encircling said screws, which structure has not been shown in the drawings. Screws I 48 screw into a mounting block I49 which is held attached to the bar I35 on one side thereof by means of a. screw I5I.

The group I31 includes leaf springs I52, I53 and I54 which are constructed identical with the leaves of the group I36 and which are similarly separated through insulated spacers I55. This group of springs is attached by means of screws I56 to the block I49, the same as the group I36 and is disposed on the opposite side of said block. Group I38 includes leaves I51, I58 and I59 and group I39 includes leaves I6I, I62 and I63. All of these leaves are mounted in identically the same manner as. the leaves of the previous group and are attached to the bar I35 on the opposite side thereof.

For operating the key, a cam lever I64 is employed which consists of a plate-like portion I65 arcuate in form which is pivoted between two cars I66 formed on the connecting portion I34 of frame I 3!. A pin I61 passes jointly through said ears and plate-like portion and forms a pintle on which said cam lever swings. A handle I68 is attached to said cam lever and serves as a means for manipulating the same. The platelike portion I65 has attached to it a pin I69 which has mounted on opposite sides thereof rollers I1I. These rollers are constructed of insulating material such as fiber or any of the phenol formaldehyde products. One of the rollers I1I is adapted to engage cams I12 and I13 formed on the switch leaves I42 and I53 and the other of said rollers is adapted to engage similar cams formed on the switch leaves I58 and I62, as best shown in Fig. '1. When the cam lever is swung downwardly as viewed in Fig. 6, roller I1I moves the cam I12 upwardly breaking the circuit between leaves I42 and I43 and connecting a circuit including leaves MI and I42. When the handle I68 is moved upwardly, roller I1I operates in the same manner with reference to leaf I 53 opening the circuit through leaves I52 and I53 and connecting a circuit through leaves I53 and I54. At the same time a corresponding opening and connecting of the leaves of groups I38 and I39 occurs, due to the other roller I1I on the opposite side of the plate-like member I65 of the cam lever I64.

The various leaves of the cam key I28 are connected together as shown in Fig. 7. A conductor I14 connects the leaves MI and I63 together. A conductor I15 connects the leaves I43 and I59 together. Another conductor I 16 connects the leaves I52 and I6I together. A conductor I11 connects the leaves I53 and I62 together and a conductor I18 connects the two leaves I54 and I51 together. The other conductors of the cam key are connected in the circuit II as will be subsequently more fully described.

The three call devices I5, I6 and I1 being identical in construction, only the call device I5 will be described in detail which is shown in Figs. 2, 3, 4 and 5. This device comprises a panel I 8I constructed of insulating material which is mounted upon a base I82. The plate I8I is smaller in dimensions than the base I82 which projects marginally outwardly beyond the same. Enclosing the entire mechanism is a case I 83 constructed with side walls I84 and I85 and with end walls I86 and I81. A top I88 is connected to all of said walls. The lowermost portion of case I83 is open and is of such dimensions as to fit about the panel I8I. The lowermost edges of the walls I84, I85, I86 and I81 rest directly upon the base I82. Case I83 is secured to the base I82 by means of countersunk machine screws I89 which are screwed into angle brackets I 9I attached to through the panel I8I.

structed with a base portion 20L This base portion is attached to the panel I8I by means of countersunk machine screws 292 which are threaded into said base portion and which extend At the upper end of the upright I99 is provided a forked bearing 294 which rotatably supports a pintle 295. Secured to the pintle 295 is an armature 256 formed with a cross head 299 adapted to be attracted by the ires ends of the cores I93 and I94 of the magnet I92. A screw 29? is threaded into the armature 206 and engages a member 298 extending out wardly from the upright I99. This screw limits the downward movement of the armature 233 -and prevents the cross head 259 from sticking to the ends of the cores I93 and I94. Issuing upwardlyfrom the member 298is a bracket 299. An adjusting screw 2i I is threaded in this bracket and engages the armature 296 and serves as a limit for the upward movement of the same. By

means of this screw the'cross head 299 is prevented from moving too far away from the magnet. A compression coil spring 2I2 acting between the armature 295 and the member 238 urges the said armature away from the cores I93 and I94 and causes the said armature to normally assume the position shown in Figs. 3 and 5.

For operating the'call device a clock mechanism is employed which is indicated in its entirety by the reference numeral 2I3. This clock mechanism comprises two bearing plates 2 I5 and 2I5 which are constructed at their lower ends with flanges 2I6 and 2I'I. Countersunk machine screws 2I8 pass throgh the panel MI and are threaded into the said flanges. Spacer sleeves 2I9 are disposed between the bearing plates 2M and 2I5 and machine screws 22I pass jointly through said plates and sleeves and hold the plates assembled in spaced parallel relation. Journaled in the two plates 2 I4 and 2I5 is a main arbor 222 which projects beyond the plate M4 and has attached to it one end of a spiral spring 223. The other end of this spring is attached to a post 224 secured to the plate 2M. The other end 225 of arbor 222 projects outwardly through an opening 226 in the wall I85 of case I83 and has attached to it a finger plate 22'! by means of which the arbor 222 may be rotated. Between the two plates 2M and H5 is rotatably mounted on the arbor 222 a gear wheel 229. This gear wheel has attached to it a pawl 229 (Fig. 5) which is adapted to engage a ratchet 23I rigidly secured to arbor 222. A 0 spring 232 attached at one end to gear wheel 228 engages at its other end the pawl 229 and holds the same into engagement with the ratchet 23I. The gear wheel 228 meshes with a gear pinion 233 fast on another arbor 234. This arbor is similarly journaled in the two bearing plates 2I4 and 2H5. Arbor 234 has attached to it a gear wheel 235 which in turn meshes with another gear pinion 236. Pinion 233 is fast on an arbor 231 which similarly is journaled in the two bearing plates 2I4 and 2I5. Arbor 231 has secured to it an escape wheel 238 which cooperates with an escapement 239 mounted on an arbor 24L This arbor is also journaled in the bearing plates 224- and 2H5. When the spring 223 is wound up rotary movement is imparted through the gear train to the escape wheel 238 which imparts an oscillatory movement to arbor 24I. Attached to the arbor 24H is a weight 242 which times the oscillation of the arbor 24 I. This icontrols the time taken for the spring to unwind and gives sufficient time for the operation of the call device.

The call device includes a switch mechanism best shown in Figs. 2 and 4. This switch mechaism comprises a mounting block 243 which is constructed of fiber or some other similar insulating material. The mounting block 243 is secured to bearing plate M5 by means of machine screws 244 which extend through the said block and are threaded into said bearing plate. Attached to the mounting block 243 are two switch leaves 245 and 243 constructed of spring material which are formed at their ends with ears 241 bent outwardly therefrom. Rigidly secured to the arbor 234 is a hub 248 which has attached to it two disks 25I and 252. The disk 25f is constructed with a certain number of notches 253 which are spaced in a predetermined manner. The ear 241 of switch spring 246 is adapted to engage the peripheral surface of the disk 25I and operates to close the circuit when in contact therewith. When said ear comes opposite the notches 253 the circuit through said switch leaf is opened. The disk 252 is smaller in diameter than the disk 25i and is constructed at intervals about its periphery with outwardly projecting lugs 254. These lugs are adapted to be engaged by the ear 241 of the leaf spring 245. When the lug 254 is engaged with the leaf spring 245 the circuit through the said leaf spring is grounded. When, however, the car 241 of said spring is intermediate the lugs 254 the circuit through the said leaf spring is opened. The lugs 254 correspond in number and position with the notches 253and when the two switch leaves 245 and 246 are in the same plane and the ears 247 thereof at the same location the said lugs register with the notches; As the arbor 234 rotates circuits are successively opened and grounded operating in a manner to cause the recording device I8 to function and thereby make a record in the recording device which indicates the particular station at which the call device originated.

The arbor 222 is held from movement by means of a latching device best shown in Figs. 2 and 3. The armature 296 of the electromagnet I92 has attached to it an upright 255, which is provided at its outer end with a latch lug 253. This lug is adapted to engage a finger 25'! formed on an arm 258. Arm 258 is secured to the arbor 222. When the parts are in normal position the finger 251 rests upon the latch lug 256 as shown in Fig. 3. When the armature 295 of the electromagnet is attracted by the core of the same, the arm 255 is swung toward the left as viewed in Fig. 3 and thelatch lug 256 is disengaged from the finger 25f. Arbor 222 then commences to rotate, at the same time rotating arbor 234 and the two disks 25! and 252 attached thereto in the direction indicated by the arrow in Fig. 2. This successively makes and breaks the respective circuits controlled by said disks.

After the arbor 234 has made a complete revolution a pin 259 fast on disk 25I' engages an arcuate surface 25I on the arm 258 which terminates the movement of the clock mechanism and said arbor 234. When this occurs the arrangement of the contacts is such that the circuit through the spring leaf 245 is closed and that through the spring leaf 245 is opened. The device can be manually reset by rotating the finger piece 221 in a clockwise direction as viewed in Figs. 2 and 5. To limit such movement a stop 262 is employed which is attached to the arm 258 and which engagesthe surface of the disk 25L The manner of connecting up the various protective devices of the invention at the subscriber's station will now be described in detail. The side I3 of the line I2 is directly connected to contact III of the pressure responsive switch 403. The other contact I09 of said switch is connected to a resistance 263 by means of a conductor 264. The resistance 263 is located in close proximity to said pressure switch or may be made a part thereof by housing the same in some portion of case I84 of said pressure switch so that it becomes impossible to tamper therewith. Resistance 263 is connected by means of a conductor 264 with the contact I I8 of thermostat I I 5. The spiral I I1 of this thermostat is connected by means of a conductor 265 with another resistance 266 which is disposed in close proximity to the thermostat the same as the resistance 263. The resistance 266 is connected by means of a conductor 261 to a similar resistance 268 used in conjunction with the call device This resistance is connected by a conductor 269 to the frame of the said call device, said frame being in turn directly connected to the two disks 25I and 252. The switch leaf 245 of call device I5 is connected to ground by a conductor 21I while the switch leaf- 246 is connected by means of a conductor 212 to one end of the foil I24. The other end of the foil is connected by a conductor 213 to a resistance 214. This resistance and the resistance 268 are associated with the call device I5 and the foil I24 in identically the same manner as the resistances 266 and 263 previously referred to. A conductor 215 runs between the resistance 214 and another resistance 216. This resistance is in turn connected by means of a conductor 211 to the frame of the call device I6. A conductor 218 extends between the switch leaf 246 of call device I6 and the switch leaf I58 of cam key I28 as shown in Fig. '7. Switch leaf 245 of call device I6 is grounded through a conductor 216. The conductor I18 of cam key I28 is grounded through another conductor 219. Switch leaf I42 of this cam key as shown in Fig. 7 is connected by means of a con ductor 28I to a resistance 282. This resistance is in turn connected by means of a conductor 283 to a similar resistance 284. Resistance 284 is connected by means of a conductor 285 with the frame of the call device I1. The side I4 of the main line I2 is directly connected to the switch leaf 246 of said call device, while the leaf 245 of said call device is grounded through conductor 260. It will thus be seen that the protective devices are all connected in series in the operating circuit II and function as a plurality of switches, each capable of opening said circuit upon actuation thereof and certain of said switches grounding the circuit upon actuation. The switch 493 opens the circuit when changes in pressure occur. Thermostat I I5 opens the circuit when changes in temperature occur. Window foil I24 opens the circuit in case the window is tampered with or broken and the cam key I28 opens and grounds the circuit when the circuit is desired to be manually opened. The three call devices I5, I6 and I1 each functions to open and ground the circuit a successive predetermined number of times when the trip holding the. clock mechanism thereof inactive is released.

The circuit I I isa normally closed circuit, being energized from the generator 22, which circuit includes the line I2. The circuit II may be traced as follows: Commencing at generator 22 current flows through conductor 24, resistance 26, conductor IIH, rheostat I62, conductor I63, conductor 98, both of the coils 5| and 51 of relays 41 and 48, conductors 91 and 96 and up to the jack 19. Current enters the switch leaf 88 of said jack and flows successively through switch leaves 9|, 89 and 81, leaving the said jack by means of the side I3 of the main line I2 which is connected thereto. Current further flows through the main line and up to the pressure switch 483. From the pressure switch the current flows through the conductor 264, resistance 263, conductor 264, thermostat I I5, conductor 265, resistance 266 and conductor 261 up to the call device I 5. At the call device the current continues through resistance 268, conductor 269 and to disk 25I of said call device. The current continues from the said disk through the switch leaf 246, conductor 212 and through the foil I24. Current leaves the foil through conductor 213, flows through resistance 214 and conductor 215 up to the call device I6. Current then flows through said call device the same as the call device I5 and from the said call device to the cam key I28 through conductor 218. Current continues from the cam key I28, flows through conductor 283 and the call device I1 and back to the side I4 of the line I2. From the line I2 the-current flows through the test jack 18 through conductor 94, coil 65 of relay 49 and conductor 95 to ground, the generator 22 being grounded through conductor 23 completes the circuit. When any of the switches constituting the protective device of the invention are opened or if the line is broken at any locality both of the relays 48 and 49 are deenergized and the springs 63 and 13 move the connectors 59 and 68 of said relays into engagement with the corresponding contact. This closes the switches 64 and 12 and closes the circuit I9. This circuit may be traced as follows: Commencing at generator 22 current flows through said circuit from the conductor 24 through the resistance 25 and the conductor 29. Current further flows through the various switches 64 and 12 to the conductor 32. From this conductor the current divides and passes through the recording device I3, bell 33 and annunciator 34. These devices are all grounded and the generator 22 being also grounded completes the circuit. The separate circuit including conductors 46, 45 and 3| and the lamp 35 energize said lamp when the arm 42 of the annunciator 34 drops and contacts with the contact 44. The light 35 when once actuated continues to operate until manually disconnected which is accomplished by resetting the annunciator. When the circuit is opened or grounded by actuation of one of the call devices I5, I6 or I1, the recording device I8 records the signal given by said call device and indicates the particular substation from which the call is received. The recording device I8 may be of any desired construction. This particular device forming no feature of the invention has not been described though it can readily be comprehended that any suitable construction such as is now well known in the art and used for similar purposes may be employed.

In the event that the circuit II is grounded at any locality outside of the central station C the coil 65 of relay 49 is shunted out and deprived of electric energy. When this coil becomes deenergized in this manner switch 12 is closed and the circuit I0 closed and the signals operated as previously described.

To make it impossible to shunt out any of the protective switches or the protective device used in the operating circuit I I, the various resistances 263, 266, 268, 214 etc. which are disposed adjacent the respective protective device are employed. The circuit II is so balanced through the rheostat that the potential relay ll maintains the switch 56 open. The said relays and the said I resistances are so designed that if one of these resistances is shunted out the potential across the coil SI of relay d'I is sufliciently increased to cause the actuation of said relay. This closes switch '6 and the signal circuit I3 is energized which causes operation of the various signals in the said circuit as previously described. If the line I2 should become shorted at any location or if any portion of the circuit H becomes shorted, the same will operate to shunt out one or more of the resistancesv 263, 266 etc. This will have the same effect as shunting out-the single resistance and will cause operation of relay 4? which energizes the signal circuit and operates the signals therein.

My invention is adapted to function if any possible combination of ground, short or open oocurs. When the circuit II is opened at any locality either through the switches or being broken both relays 42 and 39 are operated which energizes the circuit I9. If a short occurs relay il alone is operated. If a ground occurs both relays M and 98 are operated. The same is true if both an open and'a ground occur. If a short and an open occur relay 9? alone is operated and if a short and a ground occur both relays t? and 49 are operated. It will thus be seen that no matter what method of tampering with the system is employed an indication will be given at the central station. Furthermore the particular sub-station at which the signal is given will be indicated on the recording device when the circuit is opened or tampered with at such substation.

The window foil I25 operates the call device I6. Inasmuch as the call device cannot be installed directly on the window, it becomes necessary to run wires from the foil to the said call device. If an ordinary circuit were used for such purpose it would be possible to shunt out the foil and open the Window without actuating the signalling system. To prevent this the secondary circuit I9 is employed which directly operates the call device. This circuit is actuated by the circuit 2i. These two circuits are similar in operation to the circuits I9 and II and are provided with similar protective devices by means of which it becomes impossible to tamper with the foil or to short out the same and through which actuation of the signals is made equally as positive as when the switch 493 or the thermostat I I5 is operated. This is accomplished in the following manner:

For energizing the circuits I9 and 2! a battery 283is employed which is connected at one end .to. ground by a conductor 284. This battery is connected by another conductor 285 to two resistances .296 and 28?. These resistances serve the same function as the resistances 25 and 26 and operate to control the voltage in the circuits I9 and 2 I. subscribers operating line 288 which furnishes current to the circuit 2I. An auxiliary line289 is connected to the resistance 23'! and serves to furnish current to the circuit I9.

The circuit 2| is divided into three parallel branch circuits 2Ie, 2| 1 and 2 lg, there being one such circuit for each of the call devices used with the system. In the particular instance the circuit 2Ie serves the call device I5, and is actuated by the thermostat IIIS, circuit 2If serves the call To the resistance 286 is connected a device It and is actuated by foil I25 while the circuit 2 lg serves the call device I! and is actuated by cam key I29. Inasmuch as all of these circuits are identical in all respects and in the operation thereof, only the circuit 2 If will be described in detail.

In the circuit 2| j are provided three relays 29I, 292 and 293 which are identical with the relays 3'1, 38 and 99. The relay 29I comprises a coil 294 and two contacts 295 and 296 adapted to be connected together through a. connector 2971 operated by a plunger 298 movable within the coil 292. These contacts and connector form a switch indicated by the reference numeral 289. A spring 339 holds the switch 289 open. Relay 295 is a potential relay the same as the relay 9'3. Relay 292 comprises a coil 299, two contacts 235 and .392 and a connector 394 operated by a plunger 395 movable within the coil 299. This connector and contacts constitute the switch indicated in its entirety by the reference numeral 299. A spring 390 serves to close the said switch when the relay is deenergized. Relay 293 similarly comprises a coil 396, two contacts 391 and 399 and a connector 399 adapted to be operated by a plunger 3 movable within the coil 396. Said connector and contacts form a switch indicated in its entirety by the reference numeral 3I9. A. spring 329 closes the switch 3H] when relay 293 is deenergized.

The various relays 29I, 292 and 293 are connected in the circuits 2| and I9 in the following manner: The circuit 2| includes a conductor 3I2 which is connected to the line 288 and to a rheostat 3 I 3. Rheostat 3 I 3 is connected by means of a conductor 3% with the coils 294 and 299 of relays 29I and 292. These-coils are further connected together by means of a conductor 3! 5 which in turn is connected to a conductor 3I6. Conductor 359 is connected to one end of the foil I25. The other end of the foil is connected by means of a conductor 3| I to a resistance 3I8. Resistance 3I8 is connected by means of a conductor M9 to one end of the coil 396 of relay 293. The other end of said relay is connected by a conductor 32I toground. It will thus be found that the two coils of the relays 29I and 292 are connected in parallel and in series with the foil I25 and the coil of the relay 293, the said circuit receiving energy from battery 293 through the resistance 236. The circuit 2! f is a normally closed circuit and when closed maintains the three switches 289, 299 and 3H} open. The rheostat M3 is adjusted so that if the resistance 3I8 is shorted out,'the potential across the coil 294' increases sufliciently to actuate the relay 29I which closes the switch 299.

The line circuit I9 as previously stated includes the auxiliary line 289. This line is connected by means of conductors 322, 323 and 324 to the con tacts 295, 3M and 301 of switches 239, 299 and 959 respectively. The other contacts 296, 302 and 393 of said switch are connected by conductors 325, 326 and 321 to a common conductor 328 which in turn is connected to the electromagnet I92 of call device I9. The other side of this electromagnet is connected by a conductor 329 to ground. It will hence be seen that when any of the three switches 289, 293 and 3I9 are closed that a circuit is completed from the battery 283 through the electrcmagnet 592 of said call device to the ground. This circuit actuates the call device which in turn operates the signal circuit and at the same time causes the recording device I8 to function. In order to render the call devarious signals absolutely positive.

vice I5 absolutely positive the disk 252 and switch leaf 245 are employed. While the circuit is held open through the disk 25I and switch leaf 246 the same is being grounded through the other disk and switch leaf. This causes an alternate operation of the circuit through the relays 49 and 41 which procures positive energization of the circuit Ill.

The relays 29L 292 and 293 and the call device I6 may be conveniently placed within a single case and the said case locked so that access thereto is prevented. All of the wire of the circuit I9 may hence be concealed and only the wiring of circuit 2| exposed. Any tampering with the circuit 2! will cause actuation of the circuit I9 the same as described in conjunction with the circuits I and II. Actuation of circuit I9 procures the corresponding actuation of circuits II and I0 and the rendering of the signal.

The circuits Zle and My are connected with the thermostat H and the cam key I29 respectively. Inasmuch as these circuits are identical with the circuit 2| ,1 and the manner of connecting the same is identical with that previously described, the said circuits will not be described in detail.

My invention operates in the following manner: If the pressure switch 403 is opened or if the thermostat I I5 is opened circuit I I is opened and relays 48 and 49 are deprived of energy and the switches 64 and 12 close energizing circuit ID. This operates the various signals 33, 34 and 35. The same is true if the foil I24 is broken. If the switch I28 is operated manually by swinging the handle I68 in either direction the circuit is first opened and then grounded. This causes the operation of first both relays 48 and 49 and then relays 4'! and 49, making the actuation of the If an attempt is made to shunt out any of the resistances 266, 214, 282 or'284, potential relay 4'! is caused to operate which again energizes circuit I9 and operates the signals. If an attempt is made to ground the circuit at any locality in the subscribers station S both relays 41 and 49 operate and the signal is given. If the line is both open and grounded then relay 49 alone operates. It will hence become apparent that it is practically impossible to tamper with the system without procuring an indication at the central station. If the window foil I25 be broken or if the resistance 3I8 be shunted out or if the circuit 2! be shorted or grounded, the three relays 29!, 292 and 293 act in identically the same manner as the relays 41, 48 and 49 and procure cnergization of the circuit I9. This has the effect of operating the call device I6. Call device It? successively opens and grounds the circuit II thereby procuring actuation of the various signals in the central station. At the same time the call device operates the recording device I8 which advises the attendant of the particular location from which the call originates. The same is true in the event the thermostat II 6 is operated or the cam key I29, the said results being procured through the circuits Me and 2Ig and circuit I9 in identically the same manner as described in conjunction with the'window foil I25, and its associated circuits.

My invention is highly advantageous in that a comparatively simple and practical system is provided by means of which any desired kind of protection may be rendered. By means of the circuits employed it becomes practically impossible to tamper with the system without causing a signal. The invention will operate indefinitely and any failure whatsoever in the system will be manifest by the operation of the signals. The system may be periodically tested to determine leakage in the circuits. The number of units in the system may be increased or reduced at any time and by means of the variable resistances and rheostats employed the circuit is balanced for such change of conditions. The system is easy to install and can be used with any type of building or similar structure. Any combination of the services desired may be readily procured. This system can be maintained at a moderate expense.

Changes in the specific form of my invention, as herein disclosed, may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. In a protective signal system, a normally closed operating circuit, a source of electrical energy in said circuit, a normally energized potential relay having a'winding in said circuit, said relay being adapted to be actuated upon the potential reaching a predetermined value, a protective device in said circuit, a resistance in said circuit in series with said protective device and positioned in close proximity thereto, an adjustable resistance in said circuit positioned at the locality of said relay, means for adjusting said resistance to prevent normal actuation of the relay when both of the resistances are in series in the circuit, and a signal operated by said relay.

2. In a protective signal system for remote signalling, a normally closed operating circuit including a line running between a central station and a subscribers station and having a loop disposed within said subscribers station, a source of electrical energy at the central station grounded on one side and connected on the other side to one side of the line, the other side of the line being grounded in the central station, a relay at said central station having a signalling switch and a coil, said coil being connected in said operating circuit, a signal circuit at said central station, said signalling switch of said relay being connected in said signal circuit, a signalling device in said signal circuit, a recording device in said signal circuit, a call device at said subscribers station having a coil and a code switch, said code switch being connected in the loop of said operating circuit and being adapted to operate said recording device through said relay, a normally closed subscribers operating circuit at said subscribers station having a run connected at one end to a grounded source of electrical energy and at its other end to a ground, a relay at said subscribers station having a coil and a switch, said coil being connected in said subscribers operating circuit near said ground, a secondary circuit at said subscribers station, the switch of said second named relay being connected in said secondary circuit, said coil of said call device being connected in said secondary circuit, and a protective switch in said subscribers operating circuit.

3. In a protective signal system for remote signalling, a normally closed operating circuit ineluding a line running between a central station and a subscribers station and having a loop disposed within said subscribers station, a source of electrical energy at the central station grounded on one side and connected on the other side to one side of the line,. the other side of the line being grounded in the central station, a relay at said central station having a signalling switch and a coil, said coil being connected in said operating circuit, a signal circuit at said central station, said signalling switch of said relay being connected in said signal circuit, a signalling device in said signal circuit, a recording device in said signal circuit, a call device at said subscribers station having a coil and a code switch, said code switch being connected in the loop of said operating circuit and being adapted to operate said recording device through said relay, a normally closed subscribers operating circuit at said subscribers station having a run connected at one end to a grounded source of e1ectrical energy and at its other end to a ground, a relay at said subscribers station having a coil and a switch, said coil being connected in said subscribers operating circuit near said ground, a secondary circuit at said subscriber's station, the switch of said second named relay being connected in said secondary circuit, said coil of said call device being connected in said secondary circuit, a potential relay at said subscribers station having a coil and a switch, said potential relay coil being connected in said subscribers operating circuit, and said potential relay switch being connected in said secondary circuit, a protective switch in said subscribers operating circuit, and a resistance in said subscribers operating circuit in series with said protective switch and in close proximity thereto.

4. In a protective signal system for remote signalling, a normally closed operating circuit including a line running between a central station and a subscribers station and having a loop disposed within said subscribers station, a source of electrical energy at the central station grounded on one side and connected on the other side to one side of the line, the other side of said line being grounded in the central station, a relay at said central station having a signalling switch and a coil, said coil being connected in said operating circuit, a potential relay at said central station having a signalling switch and a coil, the coil thereof being connected in said operating circuit, a protective device at said subscribers station in said loop, a resistance in series with said protective device and in close proximity thereto, a signal circuit in said central station, both of said switches being connected in said signal circuit and signalling means in said signal circuit operated by either of said relays.

5. In a protective signal system, a normally closed operating circuit including a main line connected at one side to a ground, a grounded source of electrical energy, connected to the other side of the line, a normally energized relay having a coil connected in said circuit in proximity to said ground, a switch mechanism in said circuit, said switch mechanism including a pair of normally closed switch elements, and a pair of normally open switch elements, one thereof being grounded, said mechanism being adapted upon actuation to first open said first named switch elements and to thereafter close said second named switch elements to first open and then ground said circuit, and a signal operated by said relay.

6. In a protective signal system, a normally closed operating circuit including a main line connected at one side to a ground, a grounded source of electrical energy connected to the other side of the line, a normally energized relay having a coil connected in said circuit in proximity to said ground, a call device, said call device having a switch mechanism in said circuit adapted to successively open and ground said circuit, actuating means for said switch mechanism, a trip including a soil for releasing said actuating means, a secondary circuit including the coil of said trip for operating said trip, a normally closed subscribers operating circuit for energizing said secondary circuit, and a protective device in said last named circuit.

7. In a protective signal system, a normally closed operating circuit, said circuit having a run grounded at both ends, a protective device in said circuit, a relay in said circuit between one of said grounds and said protective device, said protective device including two switches, one of said switches being normally closed and opening said circuit upon actuation, the other of said switches being normaly open and having a switch element connected to said circuit, and a circuit connected to the other of said switch elements and to a ground in proximity to said protective device, and means for simultaneously operating said switches.

CLARENCE C. C. EGGERS. 

